Dental implants are known in a wide variety of forms. They are usually used through screwing into the jawbone at the site of a tooth which has been extracted or has fallen out in order to hold a prosthetic mounting element or a crown as a dental prosthesis after a healing phase of three to four months. To this end, such a dental implant is usually embodied as an appropriately-shaped metal or ceramic body and shaped in the manner of a pin and has at its apical end a mostly self-cutting screw thread with which the pin is inserted into the appropriately-prepared implant bed.
As a rule, dental implants are manufactured from titanium, zirconium, niobium or tantalum or of histocompatible alloys which contain one of these elements as the main component. Moreover, dental implants are also manufactured from ceramics. The ceramics used are usually zirconium oxide-based ceramics in which the tetragonal phase is stabilized preferably through the admixture of yttrium oxide (TZP, TZP-A with aluminum oxide components) or which are reinforced through the (usually additional) admixture of aluminum oxide, aluminum oxide [sic] (ATZ ceramics). However, other aluminum oxide-based dental implants are also known.
The goal of all of these implants is that the osseous tissue be given the opportunity to quickly and permanently bond with the implant surface. There is also talk of so-called osseointegration here. In this context, it has already been known for some time that the microscopic structure of the implant surfaces has a special importance for the promotion of osseointegration. In particular, porous surfaces with a pore size in the micrometer range have proven advantageous up to now. As a result of the enlarged contact surface between implant and bone, bone growth is promoted and the rate of bone accretion after the post-operative trauma is therefore increased.
For example, ceramic-based dental implants of the above-named type are described in EP 1 450 722 B1, in which a roughening in the post element with a roughness depth of 4 μm to 20 μm is provided in order to promote osseointegration. There, surface structures are first produced through radiation treatment.
Moreover, metallic dental implants with a homogenous nanostructured surface are known from DE 20 2005 002 450 U1. As a result of an especially favorable wetting behavior, such nanostructured surfaces appear to promote the growing-in of the implants and the integration into the osseous tissue.
The methods known up to now for the surface structuring of ceramic bodies, particularly for use as dental implants, particularly comprise sandblasting, etching and laser treatment. The ceramic dental implants currently available on the market are usually sandblasted and generally have a roughness depth of 0.5 μm to ca. 4 μm.